JUPITER, Fla. — Justin Verlander took the mound for the first time as a Met — and as a 40-year-old — on Saturday. 

And he looked much like he has earlier in his career. 

Verlander struck out three and gave up a run over three innings, hitting 96 mph on the radar gun in a 15-4 exhibition win over the Marlins at Roger Dean Stadium. 

It was Verlander’s debut with the Mets, and he took notice of the change. 

“I did glance down [at my uniform] on my way out and thought, ‘This is pretty cool,’ ” Verlander said. “There’s only been a couple times in my career when I’ve changed uniforms. It’s a new fan base [and] new teammates.” 

The Mets are hoping for the same Verlander, the one coming off his third Cy Young Award, this one won with the Astros last season. 

He threw 35 pitches, and among the highlights was a slider that got Bryan De La Cruz to swing out of his helmet in the top of the first en route to Verlander’s first strikeout. 

“He’ll make the team,’’ manager Buck Showalter joked. 

Verlander also worked in the changeup he’s refining, throwing it three times. 

“Guys like him are always searching for another look and another something else in advanced meetings that [hitters] have to prepare for,’’ Showalter said of Verlander’s evolving repertoire. “They make different pitches out of the pitches they have. Hitters come back and they expect certain things and they don’t get it. Just about everybody’s got a track record against Verlander, so he’s trying to get better.” 

Verlander also took note of the new pitch clock, though he said that unlike teammate Max Scherzer, he’s not trying to use it to his advantage — not yet at least. 

Instead, the right-hander is looking forward to getting back to a more traditional preparation for the season.

He underwent Tommy John surgery after the COVID-shortened 2020 season, which knocked him out for 2021, and then last year was impacted by the MLB lockout, which truncated spring training. 

Verlander responded last season with his third Cy Young Award then signed a two-year, $86.7 million deal to head up the Mets’ starting rotation, alongside Scherzer. 

“I’m just trying to figure it out,’’ Verlander said of his new surroundings. “A lot of fun comes with that. It’s a bit nerve-racking, but new challenges help you write new, fun chapters in your life book. Hopefully this can be one of them.” 

The Mets are counting on that, and Verlander said he likes the way he feels with three weeks to go in spring training. 

“The hardest part of the season for me is getting going and getting my body used to the routine,’’ Verlander said. “Getting through three [innings] is by far what you want to do at first. The rest is secondary.’’ 

That includes fine-tuning the changeup that he intends to include more often this season. 

“I think the eye test was pretty good,’’ Verlander said. “The next thing is to look at some of the metrics.” 

A year ago with Houston, Verlander threw the pitch just 2.4 percent of the time, according to Statcast. He used it three times on Saturday, getting one swing-and-miss. 

Verlander turned down an opportunity to pitch for Team USA in the World Baseball Classic, pointing to the fact he’s just over two years removed from Tommy John surgery, is coming off a short offseason due to Houston’s World Series run and just signed a lucrative new deal with the Mets, so he’ll stick with his new teammates. 

The only other time Verlander switched teams is when he was traded from Detroit to Houston at the deadline in 2017. 

“This is my first time in spring where I didn’t really know anybody [except former Detroit teammate] Max,’’ Verlander said. “I just want to get to know the guys, and it’s hard this time of year.”